Benni McCarthy, Blackburn Rovers' leading scorer last season but more recently relegated to the fringes, opened his account for the current campaign to settle a closely fought tie between a Nottingham Forest side struggling near the foot of the Championship and what was effectively the Premier League club's reserve XI.

If there was a freakish element to the South African's first-half winner, a free-kick which evaded friend and foe alike in a congested six-yard area, there was nothing flaky about the 73rd-minute penalty save which confirmed Blackburn's advance to the last 16. Jason Brown, the Welsh goalkeeper whose only previous first-team experience this season was in the second-round stroll at Gillingham, saved brilliantly to keep out Dexter Blackstock's well-struck kick.

During the Brian Clough era, Forest often gave a fresh twist to an old adage by concentrating on the league cup. Six times they contested the final and on four occasions they won the trophy, in its various incarnations. But priorities change, for clubs and fans alike, and even with the upper tiers of three stands closed, the atmosphere was subdued.

Forest settled the quicker, perhaps not surprising given that Sam Allardyce rested 10 of the Blackburn side that lost at Everton on Sunday. The only player to start both games was Míchel Salgado, the 33-year-old former Real Madrid defender who here played alongside 17-year-old Phil Jones.

The Spaniard found himself up against Nathan Tyson, a striker being deployed as a left-winger. Without recourse to corner flags, Tyson unsettled him by virtue of sheer pace. On leaving his marker floundering in the 16th minute, he was pulled back, rugby-style, and Salgado was booked for his trouble.

Billy Davies, the Forest manager, had bemoaned wasted chances in Saturday's home defeat by Blackpool, and the pattern looked to be repeating itself in the first half. Blackstock got a thigh rather than a foot on Joe Garner's header; Wes Morgan sliced wide when a free-kick fell to him 12 yards out; and Tyson's flick flashed inches past the near post.

Sure enough, Blackburn stole ahead with their first effort on target eight minutes before half-time. From a free-kick on the left flank McCarthy's right-footed delivery flashed through a crowded penalty area and into the far corner of Paul Smith's net. Forest's frustration promptly intensified when Robert Earnshaw's 25-yard free-kick hit the angle of post and bar.

The referee, Michael Oliver, had infuriated the crowd by failing to caution Ryan Nelsen for a high challenge on Blackstock. Later, when he pedantically made Forest move the ball a matter of inches twice as they shaped to take a free-kick, the exaseration from the stands was vociferous.

A largely youthful Blackburn team, who were on the back foot until they scored, gained in confidence. The Canadian Junior Hoilett and Frenchman Steven Nzonzi caught the eye in midfield, while the £6m Croatia striker Nikola Kalinic overcame a languid start to show some neat touches.

McCarthy might have doubled Blackburn's haul, only to head wide when unmarked. Salgado's discomfort with Tyson ended shortly after the hour, when he was replaced by Lars Jacobsen.

Forest were awarded a penalty when Steven Reid handled with 18 minutes remaining, but Brown dived to his left to parry Blackstock's kick and Blackburn cleared the ensuing scramble.